Вычислить количество отрицательных элементов каждого столбца матрицы- QBasic(Бейсик)

CLS
RANDOMIZE TIMER
INPUT "vvedite n"; n
DIM a(n, n)
FOR i = 1 TO n: FOR j = 1 TO n
        a(i, j) = INT(RND * 20 - 10)
NEXT: NEXT
FOR i = 1 TO n: FOR j = 1 TO n
        PRINT a(i, j);
NEXT: PRINT: NEXT
FOR j = 1 TO n: k = 0: FOR i = 1 TO n
        IF a(i, j) < 0 THEN k = k + 1
    NEXT
    PRINT "nomer stolbca ="; j; "kol-vo otricatelnyh jelementov:"; k
NEXT